The present invention relates generally to prosthetic devices and, more particularly, to a male coupling component, conventionally known as a xe2x80x9cplunger pin,xe2x80x9d extending from a sleeve or liner worn on the patient""s residual limb that is adapted to lock within a female coupling component, conventionally known as a xe2x80x9cshuttle lock,xe2x80x9d which is mounted within the rigid socket assembly of the prosthetic limb.
FIG. 1 shows a prior art socket assembly for a prosthetic limb. The prior art socket assembly includes a rigid molded plastic socket 10 sized and shaped to receive the patient""s residual limb therein, a locking device 12 (such as a xe2x80x9cshuttle lockxe2x80x9d) positioned at the distal end of the rigid socket 10, interconnection components 14 for maintaining the lock 12 within the socket and for mounting other components of the prosthetic limb to the distal end of the socket, and a silicone sleeve 16 adapted to be snugly fitted on (rolled onto) the patient""s residual limb. This silicone sleeve 16 includes a plate 18 molded therein having an internally threaded boss 20 extending therefrom. A plunger pin 22 includes a externally threaded proximal end 24 adapted to be attached to the internally threaded boss 20 of the attachment plate 18 and includes a racheted distal end 26 that is adapted to be received within the center hole 28 of the lock 12 and to be locked within the center hole by a spring-loaded pawl (not shown). An example of such a silicone sleeve 16 and plunger pin 22 combination is an Alpha(copyright) Locking Liner, commercially available from the Ohio Willow Wood Company, Mt. Sterling, Ohio.
To don the prosthetic limb, a patient will roll on or slip on the silicone sleeve 16 so that the plunger pin 22 extends distally from the patient""s residual limb and will then insert the residual limb into the plastic socket 10 such that the plunger pin 22 engages with the lock 12. To release the plunger pin 22 from the lock 12, a button 30 on the lock is activated to remove the pawl from within the hole 28, thereby releasing the racheted distal end 26 of the plunger pin from within the hole 28.
There are two main factors that typically cause problems with the prior art plunger pin 22 and lock 12 engagement. They are: 1) the patient has donned their locking liner 16 in a way that the plunger pin 22 is not oriented truly vertical from the center distal aspect of their limb, and 2) the lock 22 has inadvertently (during fabrication, for example) been positioned in the distal end of the socket 10 at an angle and/or dimensional offset from the distal center point. In the first case, the patient will have to re-don their locking liner 16 until the plunger pin 22 is vertical and centered on the distal end. In the second case, the socket 10 may need to be refabricated, thus positioning the lock 12 more neutrally or centered and perpendicular to the vertical axis of the limb.
The present invention provides an improved plunger pin that, in an exemplary embodiment, has multiple levels of adjustability, including rotatable, pivotal and lateral adjustability. The present invention also provides a locking liner or sleeve incorporating such an adjustable plunger pin.
A first aspect of the present invention is directed to a male coupling assembly for locking engagement with a locking device of a prosthetic limb that includes: (a) a housing having an internal cavity and a center-hole extending into its distal end, communicating with the internal cavity; and (b) a cradle retained within the cavity, having a distal-facing outer surface that is laterally slidable with respect to the proximal-facing inner surface of the cavity, and the cradle including (c) a male coupling component (such as a plunger pin, for example) extending distally therefrom, where the male coupling component is adapted to be coupled to a female locking component (such as a shuttle lock, for example) of a prosthetic limb socket assembly, and further where the male coupling component extends distally through the center-hole of the housing. Therefore, cradle, and, in turn, the male coupling component is provided with, at least, multiple degrees of lateral adjustability with respect to the housing.
In a more detailed embodiment, the cradle includes a center-hole extending axially therethrough and the male coupling component includes a ball positioned on a proximal end thereof, where the ball has a diameter larger than the diameter of the center hole of the cradle, and where the ball of the male coupling component is seated in the center hole of the cradle to provide a ball joint coupling between the cradle and the male coupling component. Therefore, the male coupling component also has multiple degree of rotational and/or pivotal adjustability. In a further detailed embodiment, the male coupling assembly further includes a resilient shock absorber operatively incorporated between a male coupling component and the housing. In a more detailed embodiment, the resilient shock absorber is positioned, at least partially, between the proximal end of the male coupling component and the inner distal-facing surface of the cavity. In a further detailed embodiment, this resilient shock absorber is a cushion. In yet a further detailed embodiment, the distal-facing outer surface of the cradle has a substantially is domed shape and the proximal-facing inner surface of the cavity has a complimentary concave shape.
In an alternate detailed embodiment of the first aspect of the present invention, the distal-facing outer surface of the cradle has a substantially domed shape and the proximal-facing inner surface of the cavity has a complimentary concave shape.
In another alternate detailed embodiment of the first aspect of the present invention, the male coupled assembly further includes a fastener extending from a proximal end of the housing, which is adapted to releasably mount the male coupling assembly to a distal end of a liner, sleeve or socket worn on a patient""s residual limb. In a more detailed embodiment, the fastener is an externally threaded boss that is adapted to be threaded into an internally threaded nut or projection extending from a plate integrally molded within, or otherwise attached to the liner, sleeve or socket worn on the patient""s residual limb.
In another alternate detailed embodiment of the first aspect of the present invention, the housing of the male coupling assembly is integrally molded within the liner, sleeve or socket that is adapted to be worn on the patient""s residual limb.
In yet another alternate detailed embodiment of the first aspect of the present invention, the housing includes a threaded outer circumferential surface that is adapted to be threaded into a threaded inner circumferential surface of a cavity extending into a distal end of the liner, sleeve or socket that is adapted to be worn on the patient""s residual limb.
In yet another alternate detailed embodiment of the first aspect of the present invention the male coupling component is a shaft having a plurality of tapered annular ribs longitudinally distributed therealong, where the annular ribs taper towards the distal end of the shaft. Therefore, the male coupling component is a plunger pin adapted for engagement with a spring-loaded pawl of the female locking component. In a further detailed embodiment, the cradle includes a center hole extending axially therethrough and the shaft of the male coupling component includes a ball positioned on a proximal end thereof, the ball has a diameter larger than the diameter of the center hole of the cradle, and the ball is seated in the center hole of the cradle to provide a ball joint coupling between the cradle and the shaft of the male coupling component. Therefore, the male coupling component is provided with multiple degrees of rotational and/or pivotal adjustability. In a further detailed embodiment, the male coupling assembly further includes a resilient shock absorber operatively incorporated between the male coupling component and the housing. In yet a further detailed embodiment, the resilient shock absorber is positioned, at least partially, between the ball positioned on the proximal end of the male coupling component and the inner distal-facing surface of the cavity. In a further detailed embodiment, the resilient shock absorber is a cushion. In yet a further detailed embodiment, the distal-facing outer surface of the cradle has a substantially domed shape and the proximal-facing inner surface of the cavity has complimentary concave shape.
A second aspect of the present invention provides a male coupling assembly for locking engagement with a female locking device of a prosthetic limb that includes: (a) a base having a hole extending into its distal end and opening onto a proximal-facing surface thereof, and (b) a longitudinal male coupling component having a ball provided on the proximal end thereof, where the ball has a diameter larger than the diameter of the proximal-facing surface opening on the base; (c) where the longitudinal male coupling component extends into the proximal-facing surface opening of the hole and out through the distal end of the base, and where the ball provided at the proximal end of the longitudinal male coupling component is seated against the proximal-facing surface of the base in the proximal-facing surface opening. Therefore, a ball joint connection is provided between the longitudinal male coupling component and the base, so that the longitudinal male coupling component is provided with multiple degrees of rotational and/or pivotal adjustability with respect to the base. In a further detailed embodiment, the base includes a cavity where the proximal-facing surface opening is provided on the inner proximal-facing surface of the cavity, and the ball of the male coupling component is maintained in the cavity. In a further detailed embodiment, the male coupling assembly further includes a shock absorber positioned, at least in part, between a proximal end of the ball of the male coupling component and the inner distal-facing surface of the cavity. In yet a further detailed embodiment, the shock absorber is a cushion.
In an alternate detailed embodiment of the second aspect of the present invention, the longitudinal male coupling component is a shaft having a plurality of tapered annular ribs longitudinally distributed therealong, where the annular ribs taper towards the distal end of the shaft. Therefore, the male coupling component is adapted for engagement with a spring-loaded pawl of a female locking device of a prosthetic limb.
It is a third aspect of the present invention to provide a male coupling assembly for locking engagement with a female locking device of a prosthetic limb that includes: (a) a base, (b) a longitudinal male coupling component extending from a distal end of the base, and (c) a resilient shock absorber operatively incorporated between the longitudinal male coupling component and the base. In a more detailed embodiment, the base includes an interior cavity and a hole extending into the distal end of the base and opening into the interior cavity; the longitudinal male coupling component includes a proximal end maintained within the interior cavity, and a remaining distal portion extends out from the interior cavity, distally through the hole, and projects out through the distal end of the base; and at least a portion of the resilient shock absorber is positioned within the cavity of the base, between the proximal end of the longitudinal male coupling member and the interior, distal-facing surface of the cavity. In a more detailed embodiment, the resilient shock absorber is a cushion.
It is a fourth aspect of the present invention to provide a locking liner that is adapted to be donned onto an amputee""s residual limb that includes: (a) a sleeve having an open proximal end for receiving an amputee""s residual limb and a substantially closed distal end, and (b) a male coupling component extending distally from the distal end of the sleeve, where the male coupling component is adjustable in an angular, lateral or rotational orientation. In a more detailed embodiment, the male coupling component extends from a male coupling assembly that is mounted to the distal end of the sleeve.
In an alternate detailed embodiment of the fourth aspect of the present invention, the male coupling assembly includes a base from which the longitudinal male coupling component extends, and a resilient shock absorber operatively incorporated between the longitudinal male coupling component and the base. In yet another alternate detailed embodiment of the fourth aspect of the present invention, the male coupling assembly is releasably coupled to the distal end of the sleeve. In yet another alternate detailed embodiment of the fourth aspect of the present invention, the male coupling assembly is fixedly coupled to the distal end of the sleeve; where such fixedly coupling may include integrally molding the male coupling assembly within the sleeve.
It is a fifth aspect of the present invention to provide a male coupling assembly for locking engagement with a female locking device of a prosthetic limb that includes a base and a male coupling component extending from the base, where the male coupling component is coupled to the base utilizing a ball-joint connection. In a more detailed embodiment, the male coupling component includes a ball positioned on a proximal end thereof, and the ball is seated within the base. In a further detailed embodiment, the base includes at least a support component and a carriage component; the carriage component seats the ball of the male coupling component therein; and the carriage component is maintained within the support component and is laterally slidable with respect to the support component. In yet a further detailed embodiment, the male coupling assembly further includes a shock absorber operatively incorporated between the male coupling component and the base.
In an alternate detailed embodiment of the fifth aspect of the present invention, the male coupling assembly further includes a shock absorber operatively incorporated between the male coupling component and the base.